1. Field of Invention
This invention relates to spraying devices, and more particularly it relates to an improved multi-chemical dispensing device and method of cleaning useful to carpet cleaners.
2. Description of Prior Art
Carpet mills have for years, recommended a method of cleaning carpet known as Hot Water Extraction (“HWE”) whereby hot dilute detergent solution is topically applied to the carpet fibers then a powerful suction “extracts” the dirty water. HWE is best performed using a specialized van or trailer mounted cleaning machine or (“Machine”) capable of delivering continuously hot (>180. degree. F.) and pressurized (40 to 100 pounds per square inch, psi) simultaneous with a powerful vacuum that “extracts” moisture from fibers. HWE is best described as a two step method (see prior art FIGS. 1, 2, and 3) whereby:
The first or wash step, includes a spray application of a solution of surfactants, detergents and/or enzymes generally referred to as (“prespray”). A portable spraying device (prior art FIG. 1) known as a hand-held injection sprayer 112 is commonly used for dispensing the prepsray to the target surface 116 (prior art FIG. 2). Then, the carpet fibers are agitated (typically with a hand-held carpet rake or an electric rotary buffer) to help loosen and suspend soils, and a short dwell time of 5-15 minutes is allowed to maximize chemical action. This prespray, agitate, and wait step is similar to washing clothes whereby the washing machine fills with hot soapy water (detergent) then sloshes back-and-forth “agitating” the fibers.
The second or rinse step, requires use of a specialized tool of carpet cleaners called a (“wand”). Baig, in his U.S. Pat. No. 6,263,539 (2001) refers to the wand 114 as having a tubular pipe with a vacuum head having a vacuum channel and a spray head attachment. A solution supply hose 15 and a vacuum hose 17 extending from the work vehicle 13 to the cleaning site 14 (prior art FIG. 3) provide pressurized dilute cleaning solution and suction to the wand. A mist of hot water with a rinsing agent additive (chemical known to neutralize detergents) is topically applied through the spray head of the wand to the target surface 116 simultaneous with powerful vacuum or ‘extraction’ strokes of the wand. The rinsing agent chemically neutralizes the prespray and the extraction strokes remove (by suction) particulate and excess moisture to a waste tank at the work vehicle. Similarly, when washing clothes, spent wash water is replaced with fresh rinse water simultaneous with a spin cycle, which “extracts” (by centrifugal force) moisture from the fibers.
Carpet cleaners repeat this two-step method job after job, using their favorite group or (“suite”) of chemicals in alternating fashion; wash then rinse and sometimes a fabric protectant. Cleaners carry ample quantities of their suite of chemicals in their work vehicle.
Some systems dispense all their chemicals directly from the Machine whereby, the Machine's integral water heater, water pump, and chemical metering pump, heat and dispense hot diluted ready-to-use (“RTU”) solutions of metered chemicals from one of a plurality of 5 gallon chemical concentrate containers or “5 gallon jugs” (not shown) housed in at the Machine and delivers them through a length of solution supply hose 15 to the cleaning site 14 (prior art FIG. 2 and 3). Usually, two 5 gallon jugs are maintained; one of detergent and another of rinsing agent although, metering systems can be customized to dispense a suite of chemicals. Problems exist with systems that meter from the Machine.
Storing and transporting these 5 gallon jugs consumes the work vehicle's limited storage space and fuel; but the biggest problem with systems that meter from the Machine is the amount of time and energy expended by the operator or (“user”) making repeated trips back and forth to the Machine as the job progresses switching or refilling the 5 gallon jugs, and/or to monitoring the metering pump flow rate settings as needed during the job. Further, it takes several minutes to flush the length of solution hose extending from the Machine to the cleaning site each time the switch is made (typically 100 feet or more). Attempting to save time and trips to the Machine, users adopt shortcuts like metering just one chemical (detergent) from the Machine throughout the job, skipping the rinse altogether. Detergent left in the carpet fibers leaves a sticky residue that dulls the carpet's appearance and acts like a magnet to new soil. It is like taking the clothes out of the washing machine after the wash cycle. And people who observe this method of carpet cleaning (especially women, whom know all about washing clothes), know intuitively that something is wrong with this method. It is no wonder people say “We don't want to get our carpets cleaned because it's never the same again.”
To eliminate these repeated trips back to the Machine and still provide the necessary alternation of chemical, U.S. Pat. No. 5,871,152 to Saney discloses a remote controlled carpet cleaner which “offers a substantial increase in productivity by offering an operator the ability to remotely control and dispense required cleaning chemicals without making repeated trips between the cleaning site and a supply truck.” These remote controlled transmitter/receiver systems have been proven successful, especially in operations like truck washes (Mechatronic Products Jackson, Tenn.) where water pressures of 3000 psi and flow rates of 3-6 (gallon per minute, gpm) can flush the solution hose in seconds, but for lower pressure operations like carpet cleaning where pressures seldom exceed 500 psi and 1 gpm, remote switching does not solve the problem of flushing the length of solution hose. Trips to switch chemical are eliminated but other trips are still needed for refilling and monitoring flow rate settings during the job. The expense of such sophisticated electronics might also be prohibitive. Cleaners often revert to portable spraying devices to avoid this flushing problem; but available portable equipment introduces another set of problems.
Pump-up sprayers and electric sprayers are portable, reliable, and capable of dispensing a wide variety of chemicals hot, but both have disadvantages. Obviously, pump-up sprayers require endless manual pumping and electric sprayers require electricity and electrical cords or batteries. Refilling of these sprayers requires trips to the work vehicle for chemicals and manual mixing of RTU solutions thus there is potential for dilution error. Both types of sprayers require that RTU solution be carried throughout the cleaning site during application, which can cause fatigue.
A recent innovation in electric sprayers employs a delivery hose with memory (like a coiled telephone cord) enabling impressive aerial coverage (up to 40 feet) and reducing the fatigue associated with carrying RTU solution throughout the cleaning site. Yet, this tubing is not known to withstand the high temperatures (>180. degree. F.) required for HWE. Also, RTU solution in pump up and electric sprayers loses temperature as the job progresses. High temperature is so critical to effective cleaning that it would make sense to discard and replace lukewarm prespray mid-job if it were not so wasteful of chemical.
Various patents disclose other portable spraying devices capable of dispensing cleaning chemicals. U.S. Pat. No. 5,020,917 to Homan et al. (1991) discloses a delivery system for mixing and metering cleaning solutions from liquid bulk concentrate storage containers into on-site individual usage dispensers. This system employs a sophisticated hydraulic and electronic design and a sturdy frame. U.S. Pat. No. 6,206,980 to Robinson (2001) discloses a multi-function cleaning machine suited for janitorial cleaning operations.
U.S. Pat. No. 5,095,579 to Becker (1992) discloses a multi-use cleaning center designed for carrying groups of objects within stackable and lockable compartments safely.
These inventions provide features advantageous to fields other than the present invention's field, that is, HWE cleaning. The complexity of design and lack of portability of U.S. Pat. No. 5,020,917 to Homan et al. (1991) prohibits its application in carpet cleaning. And none of these inventions provide a way of communicating with the Machine for generating both the hot water and powerful suction necessary for achieving HWE.
Probably the most popular portable spraying device among professional carpet cleaners is the hand-held injection sprayer. It is a portable device like the pump up and electric sprayers yet it doesn't require manual pumping or use electric cords or batteries. And like the systems that meter from the Machine, the hand-held injection sprayer is capable of dispensing large volumes of continuously hot (>180. degree. F.) RTU solution without the need to carry containers of RTU solution.
The hand-held injection sprayer (prior art FIGS. 1 and 2) receives heated and pressurized water through a length of solution supply hose 15 just like the systems that meter from the Machine but chemical doesn't enter the solution hose until its distal end, where the hand-held injection sprayer is attached. Chemical is siphoned or “drawn” from a 4 or 5 quart concentrate container or (“jug”) 126 by a venturi injector 58 and then dispensed through a relatively short hose 122 connecting the hand-held injector assembly and spray gun 100 to the target surface 116. Advantageously, this short hose 122 requires less time to flush relative to the time for the system that meters from the Machine. Unfortunately, the prior art hand-held injection sprayer introduces its own problems, including the fact that it is hard to use.
Carrying the hand-held injection sprayer can be tiring. Operation requires both hands; one hand to carry the rigid elongate member 124 (prior art FIG. 2) with tethered jug 126 and the other hand to control the spray gun 100. Manipulating the length of solution supply hose 15 attached to injector assembly is difficult as any measure of hose movement is hindered by the weight and bulk of liquid-filled jug. Those skilled in the art, know of these and other problems with this spraying device.
The hand-held injection sprayer is designed to draw from only one jug at a time. Numerous jugs can be filled ahead of time, but since it is unsafe to leave a group of jugs strewn about the cleaning site 14, the user must make repeated trips to the work vehicle to retrieve and switch among jugs. Having to stop and switch or refill jugs is tedious, time consuming, and ruins user concentration.
To switch jugs, a strap 128 (prior art FIG. 1) that tethers the rigid elongate member and jug must be removed before another jug may be secured. To refill jugs, the strap and jug cap 130 must be removed before more chemical concentrate can be added. Liquid concentrates are difficult to pour through the small cap opening of the jug (approximately 1½″ diameter). Powdered concentrates are especially difficult to transfer into the jugs' small opening and even though powders are less bulky and more cost effective than their liquid equivalents, the difficulty in refilling the jug with powder actually discourages its use. The small cap also hinders dissolution of both powders and liquids.
Another problem with the hand-held injection sprayer has to do with changing the dilution setting. One must remove the strap (prior art FIG. 1), then unscrew the jug cap, then disassemble a tubing assembly 132, and swap-out a metering tip 106, then reassemble. Although this chore may seem to have been simplified with an improved version of the prior art hand-held injection sprayer (pat pending ? Hydro Force, 542 W. Confluence Ave. Salt Lake City, Utah, 84123) which allows the user to control the dilution ratio more directly by simply turning a handy knob protruding from the side of the venturi injector 58, still, there is chance for error as the user must monitor and readjust this knob each time chemical is switched during the job and any mistake will adversely affect the cleaning result. For example, if the label directions of a particular chemical, says to use 4 ounces per gallon, it would be easy to mistakenly set the knob to 4:1 instead of the correct setting of 32:1.
Because it is hard to switch, refill, and adjust the dilution ratio of the prior art hand-held injection sprayer, the user may resist refilling it at the beginning of each job or may need more than one full jugs' worth of concentrate to finish a job; in either case, the user has to stop and refill during the job. In an attempt to eliminate these frustrating delays, some users purchase additional hand-held injection sprayers and dedicate each to a specific chemical.
Injectors dedicated to individual chemicals tend to clog and malfunction; especially when sticky chemicals like presprays, or fabric protectants are used. The same chemical meant for alternation with presprays during HWE, namely the rinsing agent, is also the perfect chemical for keeping the injector free flowing. Maintenance is required to prevent these dedicated injectors from clogging, otherwise breakdowns occur and repair costs are incurred. Dedicating injection sprayers also increases equipment costs and creates storage problems in the work vehicle.
All of the spraying devices known in the art suffer from a number of disadvantages:    (i) They all have problems managing, transporting and dispensing a suite of chemicals.
Metering from the Machine requires multiple 5 gallon jugs to be maintained at the Machine. Several 5 gal containers could be premixed to make up a days' worth of chemical (typically enough to clean 1,000 sf), but this is impractical due to space consumed and the extra fuel needed to transport them from job to job. Flush times can be prohibitively long.
Pump up and electric sprayers can manage one or two chemicals in limited amounts (typically 1-4 gallons of RTU solution) but the chemical waste and labor associated with emptying and replacing chemicals mid-job prohibits the use of either of these devices as a multi-chemical dispensing device.Hand-held injection sprayer can dispense large quantities of a single chemical but the tedium of managing and transporting multiple jugs renders this device impractical as a multi-chemical dispensing device.    (ii) They all present safety problems.
Chemicals metered from the Machine are often not identifiable as they enter the cleaning site. Multiple containers accumulate throughout cleaning site creating multiple potential safety hazards.    (iii) They all require trips back to work vehicle during the job.
Metering from the Machine requires trips throughout the cleaning process for switching, refilling, and monitoring chemicals. Pump up and electric sprayers require trips to retrieve and mix chemicals. Hand-held injection sprayers require trips for secondary sprayers or pre-filled jugs. All known dispensing systems keep chemical supplies at the Machine. The user spends more and more time retrieving chemicals as the total distance from Machine to cleaning site increases.    (iv) They all have problems associated with the process of switching chemicals.
Switching among chemicals during the cleaning process is an important part of HWE. Repeated cycles of alternating prespray, rinsing agent, and protectant are necessarily applied as the job progresses from area to area throughout the cleaning site.
Chemicals and sprayers end up being strewn about the cleaning site or are kept at the work vehicle necessitating trips, which wastes time and energy. Switching chemicals during the job using known spraying devices is so time consuming, that it discourages users from doing so. Some cleaners abandon proper cleaning procedures altogether, skipping the trips and simply meter large amounts of detergent through the wand. There is little or no prespray applied, no agitation or dwell time; nor is there a rinse step. The cleaning result is visually less than desired. Customers are suspicious of the process; wondering how is it possible to do both a wash and a rinse in the same step. Their suspicions are confirmed when the carpet feels sticky once dried and when the spots reappear.    (v) They all require manual dilution adjustments during the job.
Metering from the Machine involves use of an imprecise non-calibrated knob for adjusting the amount of chemical dispensed.
Pump up and electric sprayers require manual measuring and mixing of chemicals with water thus there is potential for incorrect dilutions.
The prior art hand-held injector requires a dilution setting adjustment each time a different chemical is used. The old style requires changing of a small plastic metering tip, inside a tube, and further inside the jug. The new style has a handy adjusting knob built into the venturi injector itself; but if set incorrectly, over or under application will occur which may adversely effect cleaning results.    (vi) They all have problems associated with refilling their chemical supply containers, especially mid-job.
While metering from the Machine, 5 gallon jugs can empty or the metering pump can clog or malfunction with no indication to the user. Refilling these jugs and re-priming the metering pump requires a trip to the Machine.
Refilling pump up sprayers requires bleeding off of hard-earned pressure and electric sprayers often need re-priming after refilling. Regarding prior art hand-held injection sprayers, many cleaners would rather purchase a second one and keep it ready at the work vehicle rather than go through the arduous task of refilling the jug mid-job.    (vii) They are all tiring.
The user quickly tires from the endless trips to the work vehicle when metering chemical from the Machine. On jobs with a lot of furniture to be moved, trip times and flush times could easily take longer than the actual time spent cleaning. Pump up and electric sprayers wear the user down with endless manual pumping or electric cords. Having to carry volumes of RTU solution throughout the cleaning site is also exhausting. The prior art hand-held injector jug can get heavy and hinder solution hose control. The device is especially awkward when trying to maneuver in tight places, behind doors, and under draperies.    (viii) They all have storage related problems.
All the spraying devices known in the art take up excessive amounts of space in the work vehicle or trailer. Special built-in holders are manufactured on some Machines to house the bulky 5 gallons jugs used to meter from the Machine. Special holders are also standard on some Machines for holding pump up sprayers, electric sprayers, and hand-held injection sprayers but none are known that hold more than one of each. Yet, many cleaners necessarily carry multiple pump up, electric, and/or hand-held injection sprayers. Storage space is used up quickly.
Objects and Advantages
This invention solves all of the above identified problems by providing a single multi-chemical dispensing device and still enables the user to perform HWE using a specialized van or trailer mounted cleaning Machine as defined by guidelines set by carpet mills, respected authorities and chemical manufacturers dedicated to the field.
Accordingly, several objects and advantages of the invention are:
    (i) To provide a single spraying device, which can be used to manage, transport, and dispense an entire suite of chemicals.    (ii) to provide a spraying device which readily discloses written safety information regarding chemicals used and provides a safe place to store chemicals onsite.    (iii) to provide a single spraying device which dispenses all chemicals necessary for proper cleaning and requires no trips back to work vehicle once the spraying device is positioned onsite.    (iv) to provide a single spraying device which enables the user to easily switch among predetermined chemicals.    (v) to provide a spraying device which automatically adjusts the dilution ratio to the precise predetermined setting for the chemical selected.    (vi) to provide a spraying device which does not need refilling during a typical job (<1,000 sf).    (vii) to provide a spraying device which frees the user from manual pumping, electric cords, and/or carrying of RTU solution thus preserving user's energy.    (viii) to provide a spraying device which stores easily on any relatively flat surface in the work vehicle and remains stable without the need of any special holding racks.
A still further object of this invention is to provide a spraying device which is inexpensive and easy to manufacture which can be provided as a kit and in a variety of shapes and sizes; customizable to a variety of chemical dispensing needs. Further objects and advantages will become apparent from a consideration of the ensuing description of drawings.